"To be honest with you, it's kind of scary up here," she said from atop the Empire State Building before inviting fans inside, where she revealed the first of three surprises. "I have a new song I'm going to play you in 30 seconds. The idea [behind the song is] that I've had to learn a pretty tough lesson in the last couple of years: People can say what they want about us, at any time ... and we cannot control that. The only thing we can control is our reaction to it. I figure we have two options: We can let it change [us] ... option two is you just shake it off."

She then debuted "Shake It Off," dancing along with the crowd while the song played. It's a track that sees Swift pairing up again with pop music masters Max Martin and Shellback ("I Knew You Were Trouble," "We Are Never Ever Getting Back Together") and has The Hollywood Reporter's music editor Shirley Halperin describing it as "her pop-tastic, up-tempo version of Frozen's 'Let It Go.' "

The Big Machine Records artist also revealed that her fifth studio album is on the way, after two years in the works. "I like to work on albums for two years because two years gives you enough time to grow and change," she said. "I woke up every single day that I was recording this record not wanting, but needing to make a new style of music than I had ever made before." What resulted was an album of rebirth, she said, "the most sonically cohesive album I've ever made," and, after listening to a lot of late '80s pop, one inspired by the decade's "bright colors, bold chances, rebellion — the idea of that was so inspiring to me."

The new album — her first official pop album, according to Swift — is called 1989, after her birth year, and will hit shelves Oct. 27. It is currently available for preorder.

Additionally, the 1989 SwiftStakes — "See, it's like 'sweepstakes' but we made it annoying!" — will give away 1,000 tickets and 500 meet-and-greets to lucky fans.

For her third and final surprise, she unveiled the fan-filled music video for "Shake It Off" (see below), which was filmed two months ago. "You can tell a lot about a person by how they dance," said Swift of the video.